1. Technical Field
The present invention relates to a resonator element, a resonator, a resonator device, an oscillator, an electronic apparatus, and a moving object.
2. Related Art
In the related art, there are known resonator elements using quartz crystal. Such resonator elements are widely used as reference frequency sources, oscillation sources, or the like of various electronic apparatuses since frequency-temperature characteristics are excellent. In particular, since the frequency-temperature characteristics of resonator elements using quartz crystal substrates cut at cut angles called AT-cut show cubic curves, the resonator elements are widely used in mobile communication apparatuses such as mobile phones.
For example, JP-A-2013-172222 discloses an AT-cut quartz crystal resonator element which has a mesa structure and in which a length Mx of a vibration section (mea section) along an X axis is set to be shorter than a length Mz of the vibration section along the Z′ axis. By shortening the length Mx in this way, it is possible to increase a distance between the vibration section and a mounting portion (extraction electrode), and thus it is possible to reduce an influence of stress by mounting.
In the foregoing resonator element, it is preferable to reduce equivalent series resistance, that is, so-called crystal impedance (CI) value.